replacing the air cooled to centrifugal chiller.

**moideen** · 08-15-2012, 04:29 AM

Dears,

We are planning to withdraw our 14 year old TRANE RTAA chiller 456 ton capacity (2 No chiller, each 228 ton total 456 ton,unit model RTAA 328) and replace with either same like air cooled chiller or new water cooled centrifugal chiller. We are advised by Mitsubishi to install ETI series 450 ton centrifugal chiller and the water cooled system shall have a power consumption of 0.8 KW against 1.6 KW the existing trane chiller. The additional investment of water cooled system can cover and pay back within 2.3 year by analyzing the local electrical and water cost. I would be interesting your valuable opinions,
1. Is better to replace same brand air cooled chiller
2. Comparison the centrifugal chillers of trane vs York vs Mitsubishi vs carrier.

Regards
Moideen-dubai

**dlove** · 08-15-2012, 09:50 AM

my two cents, factor in chemical treatment and PM maintenance on all equipment to support this. But the pay back on either one is good.

**jdblack** · 08-15-2012, 12:32 PM

Water treament will be a major focus. If preventative maintenance is an issue go air cooled. Much easier to clean coils then brush out condenser barrels.

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**Nuclrchiller** · 08-15-2012, 01:22 PM

Originally Posted by jdblack

Much easier to clean coils then brush out condenser barrels.

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That's a matter of opinion.

**pecmsg** · 08-15-2012, 01:44 PM

Originally Posted by Nuclrchiller

That's a matter of opinion.

X2

**Southern Mech** · 08-15-2012, 01:55 PM

Originally Posted by Nuclrchiller

That's a matter of opinion.

X3

**Southern Mech** · 08-15-2012, 01:58 PM

Cost to go watercooled from aircooled is a big expense... Tower, pumps, building etc. me personally would put in a couple Rtac's and never skip a beat

**ga1279** · 08-15-2012, 01:58 PM

moideen- One other thing to think about you could cut down on your maint. cost by using a McQuay WMC. There is no oil and KW/ ton is a lot better then .80, something to think about. -GEO

**KnewYork** · 08-15-2012, 02:10 PM

Originally Posted by ga1279

One other thing to think about you could cut down on your maint. cost by using a McQuay WMC. There is no oil and KW/ ton is a lot better then .80, something to think about.

I think he's referring to total system kW. A York YK with VSD will do a whole lot better than .8 kW/ton as well. I think one of the problems with a Turbocor compressor in Dubai is the likelihood that it would run a full load more than it may here in the States. Turbocor compressors don't perform as well at full load as many of their competitors.

**jdblack** · 08-15-2012, 04:07 PM

Originally Posted by Nuclrchiller

That's a matter of opinion.

Okay let me rephrase --- not easier as much as less skilled labor needed

Hows that

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**Southern Mech** · 08-15-2012, 06:30 PM

Originally Posted by jdblack

Okay let me rephrase --- not easier as much as less skilled labor needed

Hows that

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Pokin fun here but it doesnt take a genius to punch tubes.

**jayguy** · 08-15-2012, 06:50 PM

Originally Posted by Southern Mech

Pokin fun here but it doesnt take a genius to punch tubes.

it is hard to clean tubes wrong...it is very easy to clean a condenser coil wrong and screw the whole thing up...

what are we up to now? X6?

**jdblack** · 08-15-2012, 09:38 PM

Originally Posted by jayguy

it is hard to clean tubes wrong...it is very easy to clean a condenser coil wrong and screw the whole thing up...

what are we up to now? X6?

You guys just love to argue. Evidently youve never seen someone try to beat a bore brush through a tube and bust it. You think its easy because you have a tube machine and skills. Take a half wit with an adjustable and some rods and brushes and have at it. Good luck

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**Tommy knocker** · 08-15-2012, 10:00 PM

2.3 years will cover the cost of a tower, piping, pumps, chemicals, etc? Go for it.

**jayguy** · 08-15-2012, 10:35 PM

Originally Posted by jdblack

You guys just love to argue. Evidently youve never seen someone try to beat a bore brush through a tube and bust it. You think its easy because you have a tube machine and skills. Take a half wit with an adjustable and some rods and brushes and have at it. Good luck

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straight rods only? that would suck.

**mikeacman** · 08-15-2012, 10:45 PM

+1 on the centrifugal payback and understand ....

You WILL HAVE TO maintain all the added equipment and have CONSISTENT and CONTINOUS water treatment being performed at ALL times on both sides , chilled water and condensor .

as far as punching tubes consider getting a self brushing system that reverses flow every xxx hours and keeps your tubes clean ...which keeps your kw per ton down...

let your water get trashed and you'll lose your savings in a hurry....it doesn't take years to happen ...i seen tubes fouled in days without proper water treatment ...

as far as a brand I would go with what is best supported by factory reps / mechanics in your area ...

On the other hand .....

That machine goes down you have no cooling ...

You lose a fan motor on an air cooled you have wiggle room ....

You have multiple screws and lose one you have wiggle room

If your going to follow a strict maintenance regimen I would still say centrifugal ...

If your gonna run it till it quits I would say air cooled

**dlove** · 08-16-2012, 01:12 AM

Originally Posted by mikeacman

+1 on the centrifugal payback and understand ....

You WILL HAVE TO maintain all the added equipment and have CONSISTENT and CONTINOUS water treatment being performed at ALL times on both sides , chilled water and condensor .

as far as punching tubes consider getting a self brushing system that reverses flow every xxx hours and keeps your tubes clean ...which keeps your kw per ton down...

let your water get trashed and you'll lose your savings in a hurry....it doesn't take years to happen ...i seen tubes fouled in days without proper water treatment ...

as far as a brand I would go with what is best supported by factory reps / mechanics in your area ...

On the other hand .....

That machine goes down you have no cooling ...

You lose a fan motor on an air cooled you have wiggle room ....

You have multiple screws and lose one you have wiggle room

If your going to follow a strict maintenance regimen I would still say centrifugal ...

If your gonna run it till it quits I would say air cooled

I agree, well said

**moideen** · 08-16-2012, 03:22 AM

Thanks your replay,
The chemical treatment and additional centrifugal maintenance cost has also included in the comparison report of air cooled and water cooled system from Mitsubishi. For your reference, please find the attached report from Mitsubishi. But do not include the overhauling charge of compressor. (As per MHI service department recommendation, every 7 year, compressor has to be overhauled) recently we have overhauled 1500 ton capacity MHI compressor, cost is 463531 AED (126182 USD)!!. Now RTAA chiller compressor is failing after 14 years, before it don’t have major maintenance, only replaced some display boards, the authorized Trane service department can remanufacture the compressor by charging 50000AED(13611 USD),but we are the energy save by using water cooled centrifugal.
Any way we are looking the same proposals from York and trane.

Thanks
Moideen-Dubai

**KnewYork** · 08-16-2012, 08:35 AM

You might want to consider another manufacturer. I know of one (York) that does not require any scheduled overhaul interval and I have seen many compressors run over 75,000 without ever being opened.

**ga1279** · 08-16-2012, 02:06 PM

My apologies to one and all as I jumped the gun with my last post, I did not realize the area we were discussing. Water treatment will be costly as your make-up water will be high and fresh water is costly there to begin with. 14 years of life out in that climate, hell I've seen them in Houston that don't last that long.-GEO